Pump



W. R. EAMES Nov. 28, 1950 PUMP Filed March 27, 1946 IN V EN TOR. Wm. TEE E. zf'eMes H TTOENE K5 Patented Nov. 28, 1950 UNITED PUMP Walter R. Eames, Warren Township, Macomb County, Mich., assignor to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application March 27, 1946, Serial No. 657,568

10 Claims.

This invention relates to pumps and more particularly to dual pump construction;

Broadly'the invention comprehends the provision of a dual pump construction incorporating pumps of a Gerotor type, wherein the pump rotors for each pump are mounted for rotation in a housing having a bore common to both pumps, separated from one another by a floating spacer plate.

Heretofore in the production of dual pump construction it has been the general practice to makethe pump housing of a plurality of segmentsjeach segment providing an individual bore for pump, and said segments'and pumps being assembled with 'a satisfactory spacer plate separating the pumps from one another with the consequence that the overall costs of the production of such pumps is rather high. The instant invention through the incorporation of novel structure details greatly reduces the cost of such pump assembly while at the same time providing operational advantages over previous structures of this nature.

An object of the invention is the provision of a dual pump assembly ofeconomical construction and efficient operation.

Another object of the invention is the provision of a dual pump construction comprising a single housing having a common bore for mounting a pair of independent pumps.

A further object of the invention is the provision of a dual pump assembly having means incorporated therein permitting the effective priming of one of the pumps from the other pump. I

A yet further object of the invention is the provision }of a dual pump assembly wherein the pumps going to make up the assembly are mounted in a common bore of an appropriate housing and separated by a floating spacer plate providing for simplified construction and improved operating characteristics.

Otheri'objects and advantages of the invention will appear from the following description taken in connection with the drawings, forming a part of the specification; and in which:

Fig. 1 is an end plan view of a dual pump assembly; and

Fig. 2 is a vertical cross sectional view taken along line 2-2 of Fig. 1.

The use of dual pump constructions has'been adopted rather extensively in the automotive and related fields where requirements demand a pair of independent pumping systems that serve separate but similar functions relative to the mechanism with which they are associated.

The instant invention is aimed at providing a dual pump assembly that is of simpler and cheaper construction than pump assemblies of this z 1 providing a much more eflicient dual pump arrangenient for certain applications.

The present pump construction comprises a pump housing'having a single bore for receipt of a pair of pumps each of the type constituting inner and outer intermeshing rotors, said inner rotor having one less lobe or tooth than the number of cavities of the outer rotor with the outer rotor axially offset with respect to the inner rotor such that the outer rotor is driven therefrom. The pumps are separated from one another by a circular spacer plate adapted to be mounted in the bore .of the pump housing and fioatable therein relative to the housing and pumps while at the same time efl'ecting a division of the bore into' two distinct pumping chambers and eifective to substantially afford complete sealing between the chambers. The pumps and floating'spacer plate are held as a unit within I the other pump.

The inner rotors of the respective pumps are secured to and driven by a common shaft which I in turn is driven from a suitable power source such as appropriate gearing of an internal combustion engine 'or'transmission. Although it is necessary that the diameter of the pumps coincide the pumps nevertheless may be made of varying capacities dependi'fg on the application thereof.

The floating spacer plate ;,aside from minimizing the number of parts constituting the pump assembly as a whole, improves in the case, of

a combination assembl of a pressure pump and a scavenge pump. In this type of arrangementl? the pressure pump, since it is always operatingj= Eat a higher pressure thamthe scavenge pump,j*} ,will cause the spacer plate'to be pressed against the rotors of the scavenge. pump effecting zero and clearance thereby assuring primin of the scavenge pump.

Referring to the drawings for more specific details of the invention, 10 represents generally a pump housing having a bore I! closed at one end and open at the other end and a bore I4 in the closed end of the housing eccentric to bore 12 for receipt of a pump shaft It in journaled relation therein.

The bore I2 is adapted to receive a pair of Gerotor type pumps l8 and 20 respectively spaced apart by a floating spacer plate 22 mountedfor rotation in the bore [2. The pumps 18 and 20 and spacer plate 22 are held in a closed assembly in'the housing 10 by a cover or end plate 24 nature previously devised while at the same time so suitably secured upon the housing as by bolts It,

The shaft I 6 in addition to being journaled in housing III is also Journaled in a bore 28 in cover plate 24 and has splined thereto the inner rotors 30 and 32 respectively of the pumps I8 and 20. A gear 34 adapted to be driven from a suitable source of power is splined to the shaft IE to thus provide a driving medium for the pumps 18 and 20.

The pumps [8 and 20 are of the type comprising inner rotors 30 and 32 having external lobes or teeth 36 and 38 respectively adapted to mesh with inner lobes or teeth 40 and 42 respectively of outer rotors 44 and 45. The outer rotors 44 and 45 have one more tooth or lobe than the inner rotors and an equal number of cavities as teeth on the outer rotors, said cavities 48 being of like figuration with the teeth or lobes of the inner rotors, and the outer rotors are mounted eccentric to the inner rotors in journaled relation in the housing bore I2 such that upon driving relation between the inner and outer rotors the outer rotors are driven therefrom and effect pumping chambers between the teeth of the respective inner and outer rotors during the rotation thereof.

The spacer plate 22 mounted between the pumps l8 and 20 is journaled in the bore l2 of housing In and divides the bore into separate chambers 50 and 52 for the respective pumps l8 and 20, and as such provides a suificiently effective seal between the pump and chamber 50 and 52. The plate 22 is provided with a central opening 54 through which the shaft [6 extends, said opening being of a size suflicient to allow free relative movement between the shaft and plate to compensate for the eccentric relation of the shaft to the bore [2 or housing ID.

The housing l2 has an appropriate intake passage 56 communicating with a suitable intake port 58 and a discharge port 60 for pump l8 whereas the cover plate 24 is provided with suitable intake and discharge passages 62 and 64 respectively communicating with intake and discharge ports 66 and 68 respectively for pump.

The dual pump assembly herein devised is adaptably mounted upon an internal combustion engine, transmission, or similar structure, and for the purpose of illustration may be of a pressure scavenge combination, that is, wherein one pump operates independently to supply lubrication to i assuring iiri niing of thesc'hVenge rotor during the .1 operation thereof. Furthermore because of the fact the spacer plate 22 has no other sealing engagement between the pumps other than its own bearing engagement a small amount of oil will leak from the pressure lubrication pump to the scavenge pump to thus afford lubrication of the parts thereof when said scavenge pump is solely principle involved is susceptible of numerous other applications that will readily occur'to persons skilled in the art. The invention, therefore, is limited only as indicated by the scope of the appended claims.

What I claim is:

1. A dual pump assembly comprising a housing having a bore open at one end and closed at the other end forming a pumping chamber therein, a pair of rotor pumps comprising pumping means mounted in the bore, a freely rotatable spaced plate mounted in the bore between the pumps relatively rotatable to the pumping means and housing, and a cover plate enclosing the pumps and spacer plate within the housing, said housing and cover plate each having suitable intake and discharge ports respectively for one of the pumps.

2. A dual pump assembly comprising a housing having a bore open at one end and closed at the other end forming a pumping chamber therein, a pair of rotor pumps comprising pumping means mounted in the bore, a spacer plate mounted in the bore between the pumps loosely rotatable relative to the housing and pumping means, and a cover plate enclosing the pumps and spacer plate within the housing, said housing and cover plate each having suitable intake and discharge ports respectively for one of the pumps.

3. A dual pump assembly comprising a pump housing having a pumping chamber therein, a pair of pumps each comprising intermeshing inner and outer rotors mounted in the pumping chamber of said housing, said pumps each being provided with inlet and outlet ports therefor arranged in the housing wall, a plate freely journaled in the housing intermediate the pumps adapted for free rotation therein during operation of the pumps, and a rotatable shaft common to both pumps splined to the inner rotors of the respective pumps.

4. A dual pump assembly comprising a pump housing having a pumping chamber therein, a pair of pumps each comprising internal-external gear members mounted for rotation in the housing pumping chamber, each of said pumps being provided with suitable intake and discharge ports communicating therewith through the pump housing and a circular plate mounted in hearing relation to the inner wall of the housing for continuous free rotation in the pumping chamber between the pumps dividing the pumping chamber into two independent pumping chambers.

5. A dual pump assembly comprising a pump housing having a uniform bore providing a pumping chamber therein and intake and discharge ports communicating with the bore, a pair of pumps each comprising pumping means mounted for rotation in the bore, a spacer plate mounted in bearing relation to the inner wall of the housing in the bore thereof with permissible longitudinal movement between the pumps dividing the bore into separate pumping chambers for the respective pumps, said spacer plate being free to rotate therein, and a cover plate secured on the housing enclosing the pumps and plate within the housing having intake and discharge ports therein communicating with one of the pumps.

6. A plural pump assembly comprising a housing having a bore forming a pumping chamber therein, a plurality of pumps of like diameter each having intermeshing gears mounted in the bore, said pumps each having intake and discharge ports therefor arranged in the housing wall and means free to rotate in the bore relative to the housing intermediate the pumps for during the operation thereof effectively separating the pumps from one another.

7. A plural pump assembly comprising a pump housing having a pumping chamber therein, a plurality of rotary pumps each comprising internal-external gear members arranged in the pumping chamber, said pumps each having intake and discharge ports communicating with the pumping chambers thereof through the housing and means continuously freely rotatable intermediate the pumps relative to the housing separating the pumps from one another and thereby providing a plurality of pumping chambers within the housing.

8. A multiple pump assembly comprising a pump housing having a single longitudinal bore therein, a plurality of separate pumping elements of dissimilar pressure ratings disposed in tandem in said bore in graduated arrangement from the higher-pressure pump to the lower-pressure pump, and at least one freely rotatable partition plate received in said bore between said pumping elements sufficiently loosely to permit longitudinal displacement with respect to bore and pumping elements and defining separate pumping compartments.

9. A multiple pump assembly comprising in combination, a pump housing having a longitudinal bore therein being enlarged in one part of the the housing and opening to the exterior, a

drive shaft axially extending through said bore, separate pumping elements tandem-disposed in said enlarged bore and made fast to said drive shaft, a partition element received in said housin; bore sufiiciently loosely to permit longitudinal displacement and loosely mounted on said shaft between said pumping elements to assure free rotation relative to said pumping elements and housing and defining separate pumping compartments, and an end closure for the enlarged bore in said housing 10. In a pump assembly, a pump housing having a single bore therein, two separate rotatable pumping elements in said bore, and a flat partition plate fitted within said housing between said pumping elements sufliciently loosely to permit longitudinal displacement with respect to said housing and pumping elements and freely rotatable with said pumping elements and defining two separate pumping compartments.

WALTER R. EAMES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 621,280 Pitt Mar. 14, 1899 672,970 Westinghouse Apr. 30, 1901 969,026 Ball Aug. 30, 1910 1,773,211 Wilsey Aug. 19, 1930 1,988,213 Ott Jan. 15,- 1935 2,236,980 Ungar Apr. 1, 1941 FOREIGN PATENTS Number Country Date 419,421 Great Britain Nov, 1 1,934 

